1. Field of the Invention
In general, the present invention relates to a submergence detection power-window apparatus. More particularly, the present invention relates to a submergence detection power-window apparatus which allows an electrical-power driven opening unit such as a window, a sunroof or the like to open by actuation of an opening switch employed in the electrical-power driven opening unit when the car submerges under water, causing a submergence detection signal to be output provided that a seat-belt loosened-state detection signal has been activated.
2. Description of the Related Art
As commonly known, a power-window apparatus employed in a car generally comprises a window operation unit provided in a door pocket on the driver-seat side or window operation units provided in door pockets on the driver-seat side and the assistant-driver-seat side respectively. As another alternative, the power-window apparatus comprises window operation units provided in door pockets on the driver-seat side, the assistant-driver-seat side and the rear-seat sides respectively.
Each window operation unit of the commonly known power-window apparatus includes window opening/closing manual switches, a driving motor for opening and closing the window and a driving control unit. The window opening/closing manual switches are a window opening switch and a window closing switch. The driving control unit drives the driving motor in a direction according to operations of the window opening switch and the window closing switch.
When a car having such a power-window apparatus submerges underwater, causing water to flow into the inside of the car, the water also enters the door pocket containing a window operation unit. With the window operation unit submerged in the water, the water also enters the window opening switch and the window closing switch. In this state, it is difficult to maintain electrical insulation between contact points in the window opening switch and the window closing switch. Thus, the contact points are connected through a relatively small resistance of the water in spite of the fact that the switch including the contact points is open. As a result, when the window opening switch is operated later, the driving control unit of the motor associated with the window opening switch does not function normally. In consequence, the window can not be opened even if the window opening switch is operated and, accordingly, the passengers are not capable of escaping from the car submerged under the water with ease.
In order to solve the problem described above, the applicant of a patent for the present invention has recently proposed a window operation unit that is employed in a power-window apparatus, installed in a door pocket on the driver-seat side and provided with a submergence detection control circuit connected to a submergence detector having a submergence detection sensor.
In the case of the proposed power-window apparatus described above, when a car having such a power-window apparatus submerges underwater, causing water to flow into the inside of the car and also to enter the door pocket on the driver-seat side, the submergence detection sensor detects the flowing water, causing the submergence detector to generate a submergence detection signal and supply the signal to the submergence detection control circuit. At that time, even if water starts flowing into the window opening switch of the window operation unit provided on the driver-seat side, within a predetermined period following the submergence state, the submergence detection control circuit causes the motor to be driven into rotation to open the window on the driver-seat side if the window opening switch employed in the window operation unit provided on the driver-seat side is manually operated. As a result, the window on the driver-seat side can be opened to allow the passengers including the driver to get out from the submerging car.
In the case of the proposed power-window apparatus described above, when water starts flowing to the inside of the car, entering the door pocket on the driver-seat side, the submergence detection sensor of the submergence detector employed in the window operation unit provided on the driver-seat side detects the flowing water, causing the submergence detector to generate a submergence detection signal and supply the signal to the submergence detection control circuit. At that time, the window on the driver-seat side can be opened by manually operating the window opening switch employed in the window operation unit provided on the driver-seat side. On the other hand, the passenger of the car normally fastens its seat belt while the car is running so that, even after the car submerges under water, the seat belt remains fastened as it is. Thus, if the window opening switch employed in the window operation unit provided on the driver-seat side is manually operated to open the window on the driver-seat side with the passenger keeps its seat belt fastened when a car with the proposed power-window apparatus described above submerges under water and the water starts flowing to the inside of the car, a large amount of water will flow to the inside of the car through the opened window. Thus, it becomes difficult to loosen the seat belt. As a result, it is too late for the passenger to escape from the submerged car.